Parametric Study on the Stability of Crown Pillars Considering MultiVariate Regression and K-Cross Validation Techniques
Bibliographic record
Abstract
The role of crown pillar between two main levels in any underground metalliferrous mine plays a pivotal role in maintaining the stability of extracted open stopes in each level.Thus, the dimension of the crown pillar left intact between the main levels in the underground should be competent enough to withstand the induced stresses developed as a result of extraction as well as blasting, especially in large scale production methods such as large-diameter blasthole stoping method.In addition to the crown pillars in adjacent levels, a barrier crown pillar of sufficient thickness is also left intact between the ultimate pit bottom and the first level of extraction.These horizontal pillars are of utmost importance as it is one of the deciding factors in determining the stability of the existing underground structures throughout the life of mine.The present study focuses on the stability of a crown pillar left intact between two main levels existing below an open pit mine operating simultaneously with the underground mine.The targeted proposed production of the underground mine is around 5 million tonne per annum.In this paper, a total of 135 finite element models of the underground mine have been analyzed considering elasto-plastic material model.The simulation models are assessed in terms of plastic damage index with variation in material properties, crown pillar thickness, stope-extraction sequence and depth of mining.Based on the results obtained, some useful conclusions have been drawn considering both multi-variate regression and k-cross validation models.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.008 | 0.014 |
| Meta-epidemiology (narrow) | 0.001 | 0.000 |
| Meta-epidemiology (broad) | 0.001 | 0.001 |
| Bibliometrics | 0.001 | 0.001 |
| Science and technology studies | 0.000 | 0.001 |
| Scholarly communication | 0.001 | 0.001 |
| Open science | 0.001 | 0.001 |
| Research integrity | 0.001 | 0.001 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".